I've now lost half of the weight I regained during my period of neglect and denial. That's nice--it's wonderful, in fact, and I feel empowered and my knees are starting to look square again--but let the record emphasize:
three months. To re-lose
seven pounds.
I don't think this is because fat-burning itself has become inherently slower or harder (due to age, or a "set point", or too many diets or whatever). It's as if the metabolic controls just need time--about two months in my case--to rev down, switch fuel sources from today's food to yesterday's stored fat, and then rev up again.
( More internal combustion metaphor within. )